Project Summary Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by impulsivity, hyperactivity, exceptional difficulty with paying attention, or a combination of all three. This disorder would benefit from an individual differences approach of study using electroencephalography (EEG) due to its heterogeneity (Franke 2019) and the fact that the basic functional deficits associated which ADHD have not been quantified with brain activity measures, even in the general population. This project focuses on studying individual differences in the construct of cognitive control, also known as executive function, in young adults across the ADHD spectrum, a group that has been shown to have pre-frontal driven, cognitive control deficits. Our group previously showed that performance on an auditory selective attention task reflects variability in overall cognitive control, as it relies on a competitive balance between bottom-up salience of sounds (like a crying baby) and volitional, top-down desires (like paying attention to a keynote speaker) (Choi et al, 2014). We hypothesize that these previously observed individual differences in performance, their EEG correlates, and other biomarkers of object-based spatial selective attention ability all reflect the spectrum of cognitive deficits in the ADHD population. This non-invasive inquiry into the neural mechanisms of attention across the ADHD spectrum is the one of several future inquiries into specific functions in neurodiverse populations?a newly emphasized frontier in mental health research. In the long-term, a better understanding of cognitive profiles and neural correlates of specific functions could point to targets for neurostimulation or biomarkers for diagnoses in the clinic. Moreover, fundamental brain science will benefit from a departure from case-control studies, as behavioral heterogeneity is become a bottleneck in neuroscience discovery. This project aligns with the larger push from the NIMH Research Domain Criteria to study specific domains of human functioning (such as cognition) and specific constructs within them (such as attention and language) separately. Furthermore, this project falls in line with the BRAIN initiative thrusts of monitoring neural activity in human neuroscience while developing new data analysis tools.